微量样品pH测量的实现

利用电化学方法将氧化铱薄膜修饰在微电极上制备微量样品pH计，此电极体积很小，测量中只需滴3~5 μL溶液即可测出测试电极与参比电极之间的电势差，然后通过数据采集卡读取数据，将电势差信号转化为数字信号，最后用Matlab拟合输出溶液对应的pH。测量结果与商用pH计基本保持一致，此电极使用方便，灵敏度高，重现性好，而且在稀、贵样品及生物样品的分析中更显示其优越性，具有广阔的发展前景。

Implementation of microsample pH measurement

A microsample pH meter was prepared by modifying Iridium oxide thin film on a microelectrode using an electrochemical method. In the measurement process, the potential difference between the test and reference electrode was determined by dropping only approximately 3~5 μL solution on the electrode which with small volume. Then, data was obtained using a data acquisition card. The potential difference signal is converted into a digital signal, and the pH value is output with the Matlab software fitting curve. The measurement results of microsample pH meter are consistent with those of commercial pH meters. The electrode is convenient,and high sensitivity and good reproducibility, and it has superiority in the analysis of rare and expensive samples biological samples. Therefore, it has broad development prospects.